Debbie Byrne, prosecuting, said: "A security guard at Sainsbury’s in Macclesfield, was contacted by anti-fraud officers about some unusual behaviour at the self-checkout tills at the store.

“This activity was the purchasing unusual quantities of loose carrots.

“Analysis of CCTV found that on December 20 the defendant is seen buying prepackaged meat worth £3.19 but substituting the weight as loose carrots valued at 11p.

“Then on December 27 she does the same again saving herself £9.50, then on January 10 she buys nine items and saves £27.16.

“On each occasion the thefts took place on a Saturday so the security guard then waited for her. On January 17 at 5pm she entered the store and attempted the same thing. She was described an uncontrollably nervous. She took £22.20 worth of items and was arrested.”

Shirley Fitton, defending, said Percival stole to save cash when she lost her job.

She said: “She had been out of work for three months.

“She said that she had got the idea from a friend and she wanted to save money.

“She said her hands shook every times she did it.

“She knew she was being watched but didn’t know how to stop. She said she was pleased she got caught.”

Magistrates fined Percival £375.

The court also heard that the supermarket had begun civil recovery of the debt.